alpha300 S – Imaging Beyond the Diffraction Limit
The alpha300 S is a user-friendly Scanning Near-field Optical Microscope (SNOM) that combines the advantages of SNOM, confocal microscopy and AFM (Atomic Force Microscopy) in a single instrument. Switching between the different modes can be easily done by rotating the objective turret. The alpha300 S uses unique micro-fabricated SNOM cantilever sensors for optical microscopy with spatial resolution beyond the diffraction limit.
The WITec Scanning Near-field Optical Microscope alpha300 S operates using a unique near-field objective. It is mounted in the objective turret and provides access to SNOM or AFM. The micro-fabricated SNOM sensors are held magnetically at the end of the objective’s arm, enabling simultaneous observation of the cantilever and sample. For quick cantilever alignment, the arm can be moved in all three dimensions by an integrated highly-precise inertial drive. The movements are controlled by the WITec Control software, which also provides convenient alignment routines. The objective not only focuses the excitation laser beam, but also the beam-deflection laser for distance control. Highly focused, ultra-stable optics guarantee low-noise measurements without interference from the two laser systems. Using standard AFM cantilevers, the alpha300 S includes full AFM capability.
- Spatial resolution beyond the diffraction limit (ca. 60 nm laterally)
- Unique patented SNOM sensor technique
- Ease-of-use in air and liquids
- Various Atomic Force Microscopy modes included
- Non-destructive imaging technique with minimal, if any, sample preparation
- Upgradeable with confocal Raman imaging in one microscope
SNOM image of a surface plasmon-polariton wave launched on a nano-structured metal grid.
SNOM image of human chromosomes in the metaphase.
SNOM Operation Modes
- Scanning Near-field Optical Microscopy (SNOM) modes: bottom up and top down mode, collection mode
- Confocal Microscopy (CM) modes:
- Fluorescence (optional)
- SNOM-AFM combinations: AFM operation modes of alpha300 A included or optional available
- Acquisition of force-distance curves and light-distance curves
- Fixed-bottom illumination
- Total internal reflection illumination (optional)
- Research grade optical microscope with 6 x objective turret
- Video system: eyepiece color video camera
- LED white-light source for Köhler illumination of tip and sample
- High sensitivity b/w video camera to view sample and SNOM/AFM tip in transmission
- Manual sample positioning in x- and y-direction, 25 mm travel
- Microscope base with active vibration isolation system
- Piezo-driven scan stage (scan range 100 x 100 x 20 µm; others optional)
- Usually 120 mm in x- and y-direction, 25 mm in height (adapter for larger heights available)
- WITec software for instrument and measurement control, data evaluation and processing